Spectral characterization of water vapour in the 920-950 nm range using Cavity Ring Down Spectroscopy
Abstract
The Institute of Environmental Physics of the University of Bremen (IUP-UB) in cooperation with the Laboratory of Molecular and Ionic Spectroscopy (LASIM) of the University of Lyon aims to determine with high spectral resolution and accuracy the absorption cross sections and line parameters of water vapour in the 920-950 spectral range. These measurements are needed for the optimal selection of laser lines for the determination of water vapour from a platform in low earth orbit within WALES (WAter vapour Lidar Experiment in Space). In this spectral range most of the existing data are based on theoretical considerations as only a very limited number of measurements are available. Therefore, these measurements will additionally provide useful information for the validation of existing data bases. Water vapour lines with cross sections in the dynamic range 10^-20 to 10^-25 cm2 molec-1 and P and T dependencies will be measured with an spectral resolution <0,15 pm and an accuracy better than 2% over the 196-300 K and 100-1020 mbar T and P range, by using Cavity Ring Down Spectroscopy. These results will be partly compared with measurements performed with high resolution Fourier Transform Spectroscopy. The set-up, measurement technique and procedure will be presented and the preliminary results at the moment of the meeting discussed.
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....9343A